Device for thermally, stably supporting a miniaturized component

ABSTRACT

The invention related to a device for supporting a miniaturized, especially electronic or optical component, including a first and a second part, the second part is affixed to the first part on one side at a fixing point, in a cantilevered manner, and supports the component. The projection of the support area of the component onto the first part lies between the fixing point and a predetermined point of reference on the first part. The position of the support area of the component on the second part is chosen in relation to the fixing point between the first and second part and the respective material for the first and second parts is chosen with a specific temperature-dependent expansion coefficient α 1  and α 2 , in such a way that the influence of the temperature-dependent expansion of the first and second part on the position of the support area of the component is at least partially offset in relation to the point of reference.

The invention relates to a device for supporting a miniaturized,especially an electronic or optical, component, according to thepreamble of claim 1.

DE 195 33 426 A describes a mechanical fastening system for modular,microoptical elements, preferably held in a housing, on a baseplate forthe production of an optical or opto-electronic layout. A support isformed with a central platform which carries a single module. At leastthree legs which are fastened to the baseplate, for example by laserspot welding or soldering, are connected to the platform in anarticulated manner, preferably by means of hinges. This known fasteningsystem makes it possible to support optical components in a shock-proofand vibration-proof manner.

It is the object of the invention further to develop a device forsupporting a component according to the preamble of claim 1 in such away that the effect of temperature changes on the position of thecomponent can be compensated as substantially as possible.

This object is achieved, according to the invention, by the features ofthe characterizing clause of claim 1.

Advantageous further developments of the subject of the invention aredescribed in the subclaims.

Basic concepts of inventive devices and methods are described below.

In a method for surface-mounting three-dimensional, miniaturized,optical devices which are suitable for automated conveyor-belt assemblywith six degrees of freedom on a support plate of optical, electronicand miniaturized mechanical components by a flux-free and precise lasersoldering method, some modifications have been made to the holding partsfor the “TRIMO SMD” technique (three-dimensional miniaturized surfacemounted devices) in order to improve the results which can be obtainedby this technique.

The support device is now composed of at least two parts which arecharacterized by low machining precision: a standard holding part, whichis produced by die forming, for example of a 0.1 mm thick metal sheet,and the support for the optical element. The shape and the dimensions ofthe holding parts are customary and in particular have been designed sothat they can hold various optical support parts. The standard holdingpart is formed from a ball socket base, which is covered with a thin tinlayer, and from two metal flaps which are arranged perpendicular to thebase of the holding part. These flaps are extremely expedient since theypermit fixing of the holding part to the optical support part andmoreover also enable the holding part to be easily gripped by a robot.

The optical element is usually positioned roughly (±0.2 mm) inside thesupport part and held by adhesive bonding or mechanical force, which isgenerally applied by a spring.

Each support part is specially processed in order to hold an opticalelement, a lens, an optical fiber or a laser diode. The distance betweenthe focal axis and the base of the holding part can be exactly set bymoving the position of the optical support part inside the holding part.They can readily be assembled beforehand in various ways, such as bylaser spot welding, adhesive bonding or electrical resistance spotwelding. As soon as assembly is complete, the holding part can be fixedto a support plate.

Since the two parts which form the support device are completelyindependent, they can be produced from different materials. Onerestriction is that the standard holding part must be produced from ametal which can be wetted with tin, otherwise a layer which can bewetted with tin has to be applied to the spherical base of the holdingpart. This layer, which can be produced in various ways, such as, forexample, by physical vapor deposition or electroplating, is rapidlyattacked by the liquid tin—unless it is very thick—and tends todissolve. After a short time, it is no longer possible sufficiently toguarantee that it constitutes a resistant and suitable boundary layerbetween the holding part and the support plate. The deposition of alayer which can be wetted with tin thus does not improve the fixingconditions and does not improve the costs and the complexity of theholding part.

The material for the production of the holding part must have sufficientdeformability to withstand the die forming process but at the same timeit may not be too weak or too soft, in order to guarantee rigid fixing.Usually, the holding part is produced from CuBe (copper-beryllium),nickel, invar or copper.

The optical support part is usually produced by processing a 1 mm thicksheet of either CuBe or invar or stainless steel or Al₂O₃. The choice ofmaterial depends on how the two parts are to be assembled.

Since the holding part is produced using a 0.1 mm thick metal sheet, itis characterized by high heat resistance, which enables the opticalsupport part to be heat-insulated. This prevents damage to the opticalsupport part during exposure to laser radiation. The heat flow whichreaches the base of the holding part encounters considerabledifficulties in being removed along the holding part, owing to its highheat resistance. Only a small quantity of heat can reach the opticalsupport part, with the result that no dangerous heating-up is caused,and this slight heating can therefore be neglected.

The fact that the energy delivered by the laser remains limited to asmall part of the holding part during the soldering process makes itpossible to limit energy wastage and to use a less powerful laserstation.

If the holding part contains an active element which generates heat,such as a laser diode or an electrical resistance, the high heatresistance of the holding part is even a disadvantage. Unless the heatgenerated by it were removed, the active element would inevitably becaused to fail, owing to its continuous heating-up.

The small dimensions do not permit the holding part to be provided witha radiator (heat sink). The use of the support plate as a radiator whichcan remove most of the heat generated is an appealing and possiblesolution. It can be achieved only if the support plate is produced usinga material having high thermal conductivity, and also only if the heatcan flow to the support plate. An inevitable consequence of this secondpoint of view is the reduction in the heat resistance of the holdingpart. Where a large quantity of heat has to be removed, a sapphiresupport plate must be used (thermal conductivity 41 Wm⁻¹/K⁻¹). In allother cases, it is more advantageous to produce the support plate frommaterials which have a much lower thermal conductivity, such as Pyrex,Al₂O₃, zerodor, quartz and float glass. The float glass is leastsuitable because it can break during the soldering process since it doesnot withstand thermal shocks.

The soldering process, which is carried out, on a sapphire supportplate, is actually extremely problematic owing to its high thermalconductivity. The amount of energy which has to be emitted by the laserin order to cause the tin layer to melt is much greater than the energywhich would be required in the case of a support plate having a lowerthermal conductivity. The existing ratio of the energy values which arerequired for a sapphire support plate and for any other support platecan be up to a factor of 2. The necessity of a much more powerful lasersoldering station consequently requires a greater investment forpurchasing the laser and also higher utilization costs.

If the support plate acts as a radiator, the holding part should becapable of transmitting to it the heat generated by the active element.This cannot actually be achieved if the holding part is characterized byhigh heat resistance. At the same time, if the holding part ischaracterized by low intrinsic heat resistance, the heat generated bythe laser during the soldering process would rapidly reach the opticalelement and would then damage it. The heat resistance of the holdingpart must change during the process: a high resistance during thesoldering process and a low resistance after the fixing means has beenproduced. This can be achieved by filling the ball socket with asuitable heat-conducting material. If 50° C. is assumed to be themaximum temperature which is not to be exceeded by any optical element,0.5 W can be removed by a holding part which is fixed to a sapphiresupport plate and whose ball socket is not filled. The energy which canreadily be removed becomes 0.75 W when the ball socket is filled with asuitable heat-conducting material.

Al₂O₃ can be used for producing a support plate. A thin sheet of Al₂O₃permits passage of the laser beam for the soldering process. Al₂O₃ hasgood mechanical properties and its coefficient of thermal conductivityis smaller than the coefficient of thermal conductivity of sapphire butat the same time is much greater than the respective coefficient ofthermal conductivity of other materials which are used for theproduction of support plates (thermal conductivity: 24 Wm⁻¹K⁻¹). AnAl₂O₃ support plate can behave as a radiator without exhibiting thedifficulties of a sapphire support plate.

The holding part has been given a spherical base because this is theideal shape for ensuring good symmetry of the soldering agent. Abalanced distribution of the mechanical parameters avoids shrinkage,which takes place during the solidification of the tin and rotates theholding part relative to the support plate. During the orientationphase, in spite of the fact that the holding part can rotate about itsoptical axis, no changes are introduced in the boundary conditions whichare present at the interfaces between the base of the holding part andthe support plate.

If the holding part were to be provided with a flat base, thesolidification of the tin would take place with an additional rotationβ, which is dependent on Y and also on the properties of the soldermaterial, if the holding part were to have been rotated (about itsoptical axis) through an angle Y during the orientation phase.

β has a direction opposite to Y. The vertical difference between thecoordinates A and B relative to the support plate after the rotation hasbeen applied is:

Dy=AB·TgY

A tin alloy solder whose melting point is 179° C. was used. Itscoefficient of thermal expansion is 24·10⁻⁶ K⁻¹. In this example, anambient temperature of 20° C. was assumed. After the solidification, thevertical difference between A and B is:

Dy+24·10⁻⁶ ·Dy·159°.

The additional rotation is equal to:$\beta = {Y - {{{Tg}^{- 1}( \frac{{Dy} + {{24 \cdot 10 \cdot {Dy} \cdot 159}{^\circ}}}{AB} )}.}}$

If a rotation of Y through 5° is considered and if AB=2 mm, theadditional rotation β would be equal to 19 mrad.

If a rotation of Y through 2° is considered and if AB=2 mm, theadditional rotation β would be equal to 7.6 mrad.

If a rotation of Y through 10° is considered and if AB=2 mm, theadditional rotation β would be equal to 37.4 mrad.

The fact of placing a thin tin layer on the holding part base does notmarkedly adversely affect the possibility of arranging its angularposition about its optical axis without the base coming into contactwith the support plate. A table is provided for this purpose, in whichthe corresponding maximum rotation to which the holding part can besubjected without it coming into contact with the support plate isstated for each vertical space between the holding part base and thesupport plate:

Space=0.1 mm, permissible angle=12.80;

Space=0.2 mm, permissible angle=31.5°.

In the case of a space>0.3 mm, a complete rotation is permitted.

The spherical base of the holding part makes it possible to obtain thebest results with regard to the accuracy of fixing. The final accuracydepends directly on the repeatability of shrinkage. Good accuracy offixing can be achieved only if the shrinkage has been compensatedbeforehand. At present, a repeatability of the vertical shrinkage of theorder of magnitude of a few microns has been measured by means of thistechnique and, if compensation is assumed, a repeatability of the totalfixing of more or less 0.5 μm can be achieved.

Since the soldering process is carried out by a robot assembly station,the accuracy of fixing is influenced by the gripper which is mounted onthe robot. The gripper must grip the holding part, position it relativeto external reference points, hold it in its position during theexposure to laser radiation and release it after it has been fixed.Owing to the small dimensions of the holding part (2×2×3 mm), it isdifficult to grip it in a constant manner. When designing the gripper,it is necessary to make a fundamental choice. One solution is to designa gripper which is infinitely rigid and itself resists the force ofshrinkage of the metal. Another possible solution is to produce agripper having well defined resilience in the vertical direction. Inthis case, the metal shrinkage would not be hindered but would rather bepermitted along an exact direction in space. It can be achieved by alinear guide having flexible rotary fastening means.

The second solution is preferred to the first one for the followingreasons:

A design which can behave nondeformably to the force generated by theshrinkage of the tin metal would be too robust to be suitable for arobot station of high accuracy. The metal shrinkage generates amechanical load which may be greater than the limiting tensile strengthof the soldering agent, and which would then lead to failure of thefastening.

An example which illustrates a simplified typical case will now bedescribed here. The thin layer is 1 mm thick and its heat shrinkage isequal to 4 μm. This value corresponds to an average of values obtainedby experiments. Where the gripper is nondeformable, the soldering wouldreact and would produce a stress which would tend to pull the supportplate a distance toward the gripper. The magnitude of the distance movedwould be: Dy=1004−1000 mm.$ɛ = {\frac{\Delta \quad 1}{1} = {\frac{1004 - 1000}{1000} = 0.004}}$σ = ɛ ⋅ 7.2 ⋅ 10⁴ = 288  N/mm²

Since the load exerted on the tin in this case is much higher than itsfracture limit, a defect would unavoidably result.

The use of a resilient design for the gripper does not adversely affectthe final accuracy of fixing if it is assumed that the gripper design issufficiently rigid to hold the holding part in a fixed position duringthe duration of exposure to radiation. The mechanical stresses actuallyoccur only if the tin layer changes its phase and returns to the solidstate. From this point onward, the deformability of the gripper isinvolved.

The necessary gripper force can be provided in various ways, but, owingto the small dimensions of the holding part, it is difficult to exert aforce with sufficient caution. Owing to the high required accuracy offixing, the holding part must be released by the gripper without itsposition being adversely affected. Most solutions where the grippingforce is generated by a mechanical effect must be neglected because theycan adversely affect the accuracy of fixing during the release phase.

The most suitable solution has proven to be a gripper whose force isgenerated by a magnet. A small magnet can be pushed inside a tube whichis produced from a nonmagnetic material. A small soft iron disk isadhesively bonded to the top of the holding part. The tube is heldvertically and the holding part which is to be gripped is pressedagainst the bottom of the tube. The dimension of the disk is slightlygreater than the external dimension of the tube. During the grippingphase, the magnet is forced close to the end of the tube. In thisposition, it can exert a sufficient attractive force which is capable ofkeeping the soft iron disk continuously in contact with the end of thetube. The use of any positioning pin makes it possible to ensuresufficient accuracy of gripping. As soon as fixing has been completed,the holding part can be released without introducing any additionalload. The magnet is raised along the tube while the soft iron diskremains in contact with the end of the tube. The force exerted by themagnet during its movement cannot influence the disk because it isalready at its end point. During the removal of the magnet, the forceexerted by the magnet becomes weaker and weaker and can be neglectedafter some time. At this time, the holding part is completely free, andno mechanical load is exerted during the release phase.

The device for fixing or holding can compensate its thermal expansionsince it is composed of two separate parts. This aspect can beparticularly expedient where a temperature gradient is present on thesupport plate at a specific time. This can occur when a support partholds an active heat-generating element, such as, for example, a laserdiode.

The holding part and the optical support part can be assembledbeforehand, a simple pair of laser spot welds being used, and eachwelding point being provided at the upper end of the flaps of theholding part. In this way, the optical support part can, owing to thetemperature gradient, expand downward relative to the holding partbecause it is connected only by its upper section. At the same time, theholding part which has the optical support part expands upward relativeto its base or to the support plate. When the two expansions havereached the same magnitude their overall effect is equal to zero withrespect to the base of the holding part, and this means that the thermalexpansion has been compensated in this respect. This compensation can beachieved either by joining a suitable pair of materials—for theproduction of the holding part and of the optical support part—or byarranging the laser welding points, which are used for fixing theoptical support part to the holding part, in the correct position.

However, complete thermal compensation relative to the support platecannot be achieved because this would also require compensation of thethermal expansion of the tin soldering. Although compensation of the tinlayer by the system geometry and by the physical properties of thematerials used would be permitted, it cannot be achieved. The spacepresent between the holding part base and the support plate cannot infact be defined beforehand. It is actually defined only during theorientation phase and then changes its value for each of the elements.The optical support part and the holding part are assembled beforehand,before the holding part is fixed to the support plate. It is thus notpossible to compensate beforehand a quantity whose value is unknown.Although the thermal expansion cannot be completely compensated betweensupport part and support plate, its influence can at least be limited.In most cases, the support plate is in any case completely exposed tothe same thermal gradient. The elements then expand with the samemagnitude and remain oriented in spite of the expansion.

Some examples are provided by the feasibility of this principle. Let usassume the use of a soldering agent comprising the alloy having thecomposition: 62Sn36Pb2Ag, whose coefficient of thermal expansion is24·10⁻¹.

The holding part can be produced by die forming of a 0.1 mm thick invarsheet whose coefficient of thermal expansion is 2·10⁻⁶K⁻¹. The opticalsupport part is produced from silver, whose coefficient of thermalexpansion is 19·10⁻⁶K⁻¹. It was assumed that the soldering agent has tofill a space of 0.2 mm for fixing. The assembly of the holding part andof the optical support part has been implemented in such a way thatcomplete compensation of thermal expansion was achieved. An operatingtemperature gradient of 50° C. was assumed. The total expansion is theresult of the difference between the upward expansion and the downwardexpansion. The upward expansion is equal to the expansion of the holdingpart plus the expansion of the soldering agent, while the downwardexpansion is produced only by the expansion of the optical support part.The total expansion can be represented by the following equation, inwhich X has been assumed to be the mutual spacing which has to be leftbetween the laser spot and the optical axis in order to obtain a totalexpansion of zero:

=Dy _(downward) −Dy _(upward) =Dy _(holding part) +DY _(soldering agent)−Dy _(optical support part)=0

 Dy=0.2·24·50·10⁻⁶+1.8·2·50·10⁻⁶ +X·2·50·10⁻⁶ −X·19·50·10⁻⁶=0

Dy=0.00042+0.00105·X=0

X=0.4 mm.

In this special case, the laser welding points must be arranged 0.4 mmabove the optical axis in order to cancel out any thermal expansion. Thedownward expansion of the optical support part is in fact equal to theupward expansion of the total holding part plus the expansion of thesoldering agent. This example shows that it is possible in principleeffectively to perform complete compensation of the system. The onlyproblem is that the value of the space between the holding part base andthe support plate, which in this case is equal to 0.2 mm, cannot bedefined beforehand.

Usually, during the assembly phase, expansion of the soldering agent iseither neglected or an average value is considered. Some examples inwhich the expansion of the soldering agent has been neglected will nowbe presented.

The case is considered in which the holding part was produced from invarhaving a coefficient of thermal expansion of 2·10⁻⁶K⁻¹, while theoptical support part was produced from copper-beryllium, having acoefficient of thermal expansion of 9·10⁻⁶K⁻¹. In this case too, thevertical expansion of the device can be represented by the followingequation:

Dy=Dy _(holding part) −Dy _(optical support part)=0

Dy=1.8·2·50·10⁻⁶ +X·2·50·10⁻⁶ −X·9·50·10⁻⁶=0

Dy=0.00018+0.00035·X=0

 X=0.51 mm

Compensation of the thermal expansion of the holding part would requirearranging the pair of laser spot welds 0.51 mm above the optical axis ofthe element.

In another case, the support device was produced from copper-berylliumwhile the optical support part was produced from copper having acoefficient of thermal expansion of 17·10⁻⁶K⁻¹. The expansion of theholding part is:

3·50·9·10⁻⁶=0.00135 mm.

The expansion of the optical support part is:

X·50·17·10⁻⁶. This results in:$X = {\frac{0.00135}{0.00085} = {1.59\quad {{mm}.}}}$

In this particular case, the thermal expansion cannot be fullycompensated, owing to the limitations of the geometry of the opticalsupport part.

The maximum permissible distance between the optical axis and the laserwelding point may not be greater than 1 mm. Since the optical supportpart has a height of 2 mm, a laser welding point may not be further than1 mm away from the horizontal center line of the optical support part.

In this case, although complete compensation cannot be achieved, it ispossible to carry out partial compensation in order to improve theaccuracy of fixing. Without any compensation, the heat shrinkage of theholding part would be 0.00135 mm. In contrast, if the maximumpermissible compensation is carried out, the result can be reduced to:

Expansion of the holding part—Expansion of the optical supportpart=0.00135−0.00085=0.0005 mm.

The solutions proposed to date are not completely fixed; instead, it ispossible to implement many modifications in order to adapt the techniqueto the requirements of different applications. For example, the supportplate used may be a silicon plate in order to make it compatible andthen directly to integrate the optical design with microelectronicmodules which are produced using silicon. Since silicon has goodtransparency for laser light having a wavelength between about 1.4 μmand 15 μm, a CO₂ laser beam can be used for carrying out the fixing.

It is possible for the same hybrid silicon module to contain the opticaldesign which is produced using the “TRIMO” (three-dimensionalminiaturized optical) technology and an “SMD” (surface mounted device)electronic module. This solution would limit the problem due to pooradaptation of the thermal expansion.

In some particular cases, fixing can be carried out by exposing theholding part to UV light for curing an adhesive between the supportplate and the holding part base, instead of carrying out a lasersoldering process. The orientation of the holding part can be performeduntil the correct position is reached. The adhesive is then exposed frombelow the support plate to the UV light beam, with the result that itpolymerizes, and fixing is then effected. Since the adhesive is ratherfluid before exposure to the UV light beam, the lower surface of theholding part can come into contact with the adhesive without any stressbeing introduced into the holding part. This solution makes it possibleto obtain bonds which achieve the required properties of rigidity andreliability only when the adhesive is not impaired by the creep effectsor aging problems.

In many cases, the optical elements used are very expensive andfurthermore the assembly requires considerable work. For this reason, itis necessary, since a replacement element cannot be provided, to developan alternative solution which makes it possible to fix an element, whosenormal fixing process has failed, to the support plate in any case. Thiscan be achieved by applying a fixed amount of tin soldering paste to theregion on the support plate where the element is to be fixed. Theoptical element is oriented relative to its external reference points,while its underside is moved into the soldering paste. The fact that thesoldering paste is particularly soft means that no mechanical stress isgenerated or need be feared. Once the optical element has beencompletely oriented relative to the laser beam to which it is exposedfrom below the support plate, it permits melting of the tin solder pastewhich adheres firmly to the support plate and the holding part,simultaneously resulting in the required fixing.

Where the exposure to laser radiation is not the most suitable methodfor melting the soldering agent, other solutions can be considered. Therequired heat can in fact be introduced either by electrical resistancesoldering or by magnetic induction soldering.

The subject of the invention is described in more detail below on thebasis of embodiments with reference to the attached drawings.

FIG. 1 shows a schematic diagram illustrating the principle oftemperature compensation in an embodiment of a support device accordingto the invention;

FIG. 2 shows a holding part in an embodiment of a support deviceaccording to the invention;

FIG. 3 shows a holding part according to FIG. 2, which is shown with asupport part for a component, which support part is coordinated withsaid holding part, and

FIG. 4 shows the holding part with support part fixed to it.

FIG. 1 shows a schematic sectional diagram of an exemplary supportdevice according to the invention, denoted in general by 1.

A holding part 3, as a first part, is fixed on a baseplate 2. Theholding part 3 is formed from a metal strip which is bent into a“U”-shape. The holding part 3 has two “U”-limbs 4, 4′ which areconnected by a curved base section 6. The “U”-limb 4′ is longer than the“U”-limb 4 and can be gripped by its extension by a robot gripper duringthe automatic assembly. The baseplate 2 is provided on its surface withsurface regions 7 which are suitable for a solder joint 8. The holdingpart 3 is soldered with its “U”-shaped base section 6 to these surfaceregions 7 of the baseplate 2. If the metal strip cannot be soldered ondirectly, it is suitably coated beforehand.

A support part 12, as a second part, which is shown in the form of arectangular plate, is arranged between the “U”-limbs 4, 4′ of theholding part 3. The support part 12 is fixed to the holding part 3.Fixing to the holding part 3 is effected at a fixing point 13 in the endregion of the “U”-limb 4 which is on the left in the diagram, and at thesame height to a fixing point 13′ on the right “U”-limb 4′. On theplate-like support part 12, the fixing points 14, 14′ are present at theleft and right lateral edges 15, 15′, respectively, but exclusivelyclose to that end edge 16 which is further away from the base section 6.Consequently, the plate-like support part 12 is fixed only on one sideor in a cantilevered manner in the region of its end edge 16. Apart fromthis fixing between holding part 3 and support part 12, there is noother rigid connection between them. The connection of holding part 3and support part 12 can be effected, for example, by spot welding.

The support part 12 is formed with a central orifice 17 in which acomponent (not shown) is supported. If the support device shown issubjected to a temperature change—for example a temperature increase,the two “U”-limbs 4, 4′, which are connected by the base section 6 tothe baseplate 2, expand, only the expansion in their longitudinaldirection being considered here to be relevant for the position of thecomponent. The distance between the fixing points 13, 13′ on the“U”-limbs 4, 4′ on the one hand and the base section 6 on the other handincreases as a result of thermal expansion, cf. the upward-pointingarrow 5. At the same time, the plate-like support part 12 also expands,namely in the direction toward the base section 6, since it is connectedin its upper section firmly to the U-limbs 4, 4′ at said fixing points14, 14′, cf. the downward-pointing arrow 9.

If the change in length of the “U”-limbs 4, 4′ between said fixingpoints 13, 13′ and the base section 6 is made just as large as thechange in length of the plate-like support part 12 between its fixingpoints 14, 14′ and the center of the orifice 17, then the distancebetween this center and the base section 6 remains constant,independently of temperature changes. FIGS. 2 to 4 show phases of theassembly of a further embodiment of a support device according to theinvention.

FIG. 2 shows a holding part 20 which is produced from a base part 21which is in the form of a ball socket and has an edge region 23surrounding an orifice 22 of the base part 21. The outer periphery ofthe edge region 23 is, for example, square. Two strip-like upright flaps24, 24′ are provided on two opposite sides of the edge region 23. As inthe case of the right “U”-limb in FIG. 1, here too the right flap 24′ isslightly longer than the left flap 24. The holding part 20 is preferablyformed as an integral unit 21, 23, 24, 24′.

FIG. 3 shows a parallelepiped-shaped support part 26 having a centralpassage 27. A schematically shown optical element 28 is arranged in saidpassage. It can be seen that the support part 26 is formed in such a waythat it can be inserted between the two flaps 24, 24′.

FIG. 4 shows the support part 26 held by the holding part 20. Saidsupport part is connected to the holding part 20 by two spot weldsopposite one another, only one of which 29 is visible. In the case of atemperature change, the two strip-like flaps 24, 24′ can expand orcontract relative to the base part 21. The same applies to the supportpart 26, but the change in length is opposite to that of the flaps 24,24′ With corresponding dimensions of the parts and choice of materialswith regard to the coefficient of thermal expansion, the distancebetween the center of the passage 27 and the base part 21 can be kept toa large extent constant independently of the temperature.

List of Reference Numerals

1—support device

2—baseplate

3, 20—holding part (“first part”)

4—“U”-limb

4′—(longer) “U”-limb

5—arrow, upward-pointing

6—(curved) base section

7—surface region on (2), suitable for (8)

8—solder joint

9—arrow, downward-pointing

12—support part (“second part”)

13—fixing point on (4)

13′—fixing point on (4′)

14, 14′—fixing points on (15, 15′)

15, 15′—lateral edges of (12)

16—end edge of (12)

17—central orifice of (12)

21—base part (in the form of a ball socket)

22—orifice of (21)

23—edge region of (21)

24—strip-like upright flap

24′—strip-like upright (longer) flap

26—parallelepiped-shaped support part (“second part”)

27—central passage

28—component; optical element

29—spot weld (“fixing point”)

What is claimed is:
 1. A device for supporting a miniaturized component,comprising a first part (3, 20) formed with a base (21) having a convexsurface and a first and a second flaps (24, 24′) arranged upright onsaid base (21), wherein a first fixing point (13) for a second part (12,26) is arranged on said first flap (24) and a second fixing point (13′,29) for said second part (12, 26) is arranged on said second flap (24′),and said second part (12, 26) supports the component (28), said secondpart (12, 26) being fixed to the first part (3, 20) between said firstand second flaps (24, 24′) at said first and second fixing points (13,13′, 29) of each of said first and second flaps (24, 24′) on oppositesides of the second part (12, 26), and a support (17, 27) for thecomponent (28) is arranged on said second part (12, 26), wherein (i) theposition of said support (17, 27) on the second part (12, 26) is chosenrelated to the first and second fixing points (13, 13′, 29) between thefirst (3, 20) and the second (12, 26) parts, and (ii) a first materialof the first part (3, 20) has a specific coefficient of thermalexpansion α₁ and a second material of the second part (12, 26) has aspecific coefficient of thermal expansion α₂ such that an influence of athermal expansion of the first part (3, 20) on a position of the support(17, 27) of the component (28) relative to the base (21) is at leastpartly compensated by an influence of a thermal expansion of the secondpart (12, 26).
 2. The device of claim 1 wherein said component (28) isselected from the group consisting of: an electronic component, and anoptical component.
 3. The device of claim 1 wherein said base (21)having a convex surface is formed as a ball socket.
 4. The device asclaimed in claim 1, wherein the second flap (24′) is formed with alength greater than the first flap (24), so that the first part (20) canbe held, moved or positioned on the second flap (24′) by a transport andpositioning device.
 5. The device as claimed in claim 1, wherein thefirst part (3, 20) is an integral unit.
 6. The device as claimed inclaim 4, wherein the first part (3, 20) is an integral unit.
 7. Thedevice as claimed in claim 1, wherein the first part (3, 20) is producedfrom a metal.
 8. The device as claimed in claim 7, wherein the metal isCu.
 9. The device as claimed in claim 1, wherein the second part (12,26) is produced from a metal.
 10. The device as claimed in claim 9,wherein the metal is Cu.
 11. The device as claimed in claim 7, whereinthe first part (3, 20) is produced from a ceramic material.
 12. Thedevice as claimed in claim 11, wherein the a ceramic material is Al₂O₃.13. The device as claimed in claim 1, wherein the second part (12, 26)is produced from a ceramic material.
 14. The device as claimed in claim13, wherein the ceramic material is Al₂O₃.
 15. The device as claimed inclaim 1, wherein the first part (3, 20) is produced from a metal alloy.16. The device as claimed in claim 15, wherein the a metal alloy is CuBealloy.
 17. The device as claimed in claim 1, wherein the second part(12, 26) is produced from a metal alloy.
 18. The device as claimed inclaim 17, wherein the metal alloy is CuBe alloy.